The present invention relates to a mechanism for rotating a stand constituting a leg portion of a monitor device or the like.
For example, a monitor device for monitoring an image outputted from a personal computer or the like adopts a stand having a horizontally rotating mechanism and a vertically tilting mechanism for optimizing orientation of a display section in accordance with an installation location of the monitor device and the viewing angle of the user operating the monitor device.
FIG. 1 is a typical side view of a monitor device having a related art stand rotating mechanism.
As shown in FIG. 1, a monitor device 40 includes a monitor section 41 containing a CRT (Cathode Ray Tube) and a CRT substrate which constitute a display section; a tilting section 42 for supporting the monitor section 41, which has on a bottom surface a spherical sliding portion rotatable in the vertical direction (shown by an arrow U or D) for changing orientation of the monitor section 41; a rotary base 43 for supporting the tilting section 42, which is rotatable in the horizontal direction (shown by an arrow L or R); and a leg section 44 for rotatably supporting the rotary base 43.
In this way, the monitor device 40 adopts the stand rotating mechanism composed of the tilting section 42 and the rotary base 43. The monitor section 41 can be rotated in the vertical direction (shown by an arrow U or D) and the lateral direction (shown by an arrow L or R) by the stand rotating mechanism, and accordingly, even when the user is not positioned directly opposite to the monitor device 40, he can take a suitable monitoring position by displacing orientation of the monitor section 41.
In addition, with respect to the stand rotating mechanism, for maintenance of a power supply cable or a video signal cable led from the monitor section 41, the horizontally rotating angle given by the rotary base 43 is limited to a value, for example, within 180.degree. (90.degree. for each of right and left sides).
Incidentally, although the monitor device 40 shown in FIG. 1 adopts the stand rotating mechanism of a three-layer structure having the tilting section 42, rotary base 43, and leg section 44, such a stand rotating mechanism has problems that the manufacturing cost is high, the strength is insufficient, and the durability and assembling performance are poor.
To cope with such problems, a stand rotating mechanism of a two layer structure is known, in which a rotary base rotatable in the tilting direction and in the horizontal direction is disposed on the leg section 44.
FIGS. 2A to 2C are typical plan views schematically showing rotation of a stand rotating mechanism of a two layer structure.
As shown in these figures, a rotation restricting section 52 is inserted between a pair of guide walls 51a and 51b. The rotation restricting section 52 has abutment planes 53a, 53b, 54a, and 54b to be abutted on the guide walls 51a and 51b in accordance with a horizontally rotational state of the monitor section. The abutment plane 53a crosses the abutment plane 54a, for example, at 90.degree., and similarly the abutment plane 53b crosses the abutment plane 54b, for example, at 90.degree..
In addition, the guide walls 51a and 51b are projectingly provided on either the rotary base or the leg section, and the rotating restricting section 52 is projectingly provided on either the tilting section or the leg section. Here, the guide walls 51a and 51b are projectingly provided on the rotary base, and the rotation restricting section 52 is projectingly provided on the leg section.
For example, FIG. 2A shows a state in which the rotating and tilting directions of the monitor section are directed to the front side. When the monitor section is tilted from such a state, the guide walls 51a and 51b are moved in the direction shown by an arrow U or D.
When the monitor section is rotated, for example, in the direction shown by an arrow R (rotational direction), the guide wall 51a is abutted on the abutment plane 53a and the guide wall 51b is abutted on the abutment plane 53b, as shown in FIG. 2B. Thus, the monitor section is rotated, for example 45.degree., rightward from the state shown in FIG. 2A, and is stopped.
When the monitor section is rotated, for example, in the direction shown by an arrow L (rotational direction) from the state shown in FIG. 2A, the guide wall 51b is abutted on the abutment plane 54a and the guide wall 51a is abutted on the abutment plane 54b, as shown in FIG. 2C. Thus, the monitor section is rotated, for example 45.degree., leftward, and is stopped.
The stand rotating mechanism of such a two layer structure is effective to reduce the number of parts and realize the low cost, high strength, high durability, and good stability as compared with the stand rotating mechanism having the three layer structure shown in FIG. 1; however, as shown in FIGS. 2A to 2C, the horizontally rotational angle is limited to a value within 45.degree. for each of the right and left sides from the center.
Accordingly, a stand rotating mechanism rotatable 90.degree. for each of right and left sides has been required to have a three layer structure, and it has presented, as described above, the problems in terms of manufacturing cost, strength, durability and the like. Besides, the stand rotating mechanism having a two layer structure has presented, as described above, the problem that the rotational angle is limited to a value within 45.degree. for each of right and left sides.